I love Facebook Promotions!
There are a few different ways to advertise on Facebook.
The most effective I have found, for a groomer is promoting posts. You can choose your target audience down to naming specific areas and only those people in those areas that have expressed an interest in certain key words that you specify in your advertising parameters. You even set your budget.
The way I have been using this is when I have a cancellation I need to fill, I will set a budget of $10 and promote a post about the available appointment. 9 times out of 10 I am getting that appointment filled. Now, I know I am spending $10 to fill that spot, but I would rather have my regular charge - $10 over $0. A neat feature is that once the appointment has been filled I can cancel the promotion and not be charged further from that point on.
Just thought I'd share. :-)